Part One: Veterinary canine urolith epidemiology: 1981-2011
Mineral composition trends have been stabilizing in recent years.
May 01, 2012
The mineral composition of uroliths in dogs has varied in the last three decades. In this article, we evaluate canine uroliths submitted to the Minnesota Urolith Center to determine whether trends during 2011 were different from previous years. We then look at what this information might mean for our patients.
Composition comparison over three decades
Possible causes of this decline in the frequency of naturally occurring struvite uroliths and a reciprocal increase in calcium oxalate uroliths include:
1. Widespread use of a calculolytic food designed to dissolve sterile struvite uroliths
2. Widespread use of maintenance and prevention foods modified to minimize struvite crystalluria—some dietary risk factors that decrease the risk of struvite uroliths increase the risk of calcium oxalate uroliths
3. Inconsistent follow-up evaluation of efficacy of dietary management protocols by urinalysis and radiography.
Likewise, the probability that > 95 percent of the canine struvite uroliths submitted to our center were induced by microbes that produced urease-producing enzymes, while < 95 percent of the feline uroliths were not associated with urease-positive microbes, is problematic. A hypothesis that might explain, at least in part, the trend toward increased calcium oxalate occurrence in both groups is the treatment of canine infection-induced uroliths with an appropriate diet and antimicrobial drugs and the treatment of sterile feline uroliths with an appropriate diet.